At six-foot-seven, James Arness— who died today at 88 — would have been a commanding presence in any medium or most any job. Luckily for him, us, and CBS, the job he found was ideal: Matt Dillon, the stalwart marshal who kept the Dodge City peace on TV's longest-running drama, Gunsmoke.

It was a role he would play for twenty years, longer than any other actor on a single primetime series. (Kelsey Grammer would eventually beat his record, but it took him two shows, Cheers and Frasier, to do so.) Along the way he became a symbol, not just of a western hero, but of what an American hero should be: Strong, compassionate, resolute, resilient, slow to anger but extremely dangerous to cross. Matt was the kind of man who inspired devotion, from viewers, from deputies, and from the beautiful bar-keep — Amanda Blake's Miss Kitty — who clearly would have kept time with Matt had he only asked.

Oddly enough, as perfect as the job was for Arness, he almost didn't get it. CBS first offered the role to John Wayne, figuring he'd be a better fit for the TV cameras than the shorter, dumpier William Conrad who originated it on the long-running radio program. But Wayne refused and, instead, recommended Arness, who surprised his mentor by turning it down.

Arness had a few good reasons. He movie career was beginning to pick up, having moved from playing The Thing in The Thing to a much more visible staring role in the sci-fi classic Them. Plus, before Gunsmoke's 1955 debut, the only westerns to crack the Top Twenty were kid stuff like The Lone Ranger and The Adventures of Rin Tin Tin.

Happily for TV history, Wayne got Arness to change his mind, in part by agreeing to introduce the first episode — and a TV legend was born. Two years later, Gunsmoke began a four-year run as America's top-rated series. And it's popularity was so steady and long-lasting, it would rise as high as Number 2 again in 1969.

As it broke the mold for the genre, Gunsmoke ushered in an entire TV era: The reign of the Adult Western. At the era's peak, there would be more than 30 westerns on the air at once. Take that, reality TV.

No show runs for two decades without change, and Gunsmoke was no exception. Milburn Stone's Doc was a constant, but otherwise, cast-members came and went. Dennis Weaver's original, limping deputy Chester gave way to Ken Curtis's shaggier Festus. Burt Reynolds spent a few years in Dodge before moving on to stardom elsewhere. The series changed nights, slots, and even lengths, starting as a half-hour show before expanding to an hour in 1961.

Yet always, holding it together, was Arness. Even when he wasn't on screen (and there were many episodes where he was mentioned more than seen), his looming presence was felt.

Mess around in Dodge City, and sooner or later, Marshall Dillon would make you sorry you did.

An intensely private man, Arness was seldom seen or heard outside of Gunsmoke's dusty confines. Many fans may never even have known he had a star for a brother, as well: Peter Graves.

Perhaps because we only saw him as Marshall Dillon, Arness was, for most of us, always Marshall Dillon. Short runs on two other series followed: How the West Was Won in 1978; McClain's Law in 1981. But no other role took, and by the late '80s, he was back to playing Matt in a scattered series of five Gunsmoke movies. And why not? He was a big man, that was his big role — and united, they played a big part in TV history.